TWI757604B - Substrate processing apparatus and substrate processing method - Google Patents

Abstract

The present invention relates to a substrate processing apparatus and a substrate processing method. According to one embodiment, a substrate processing apparatus includes: a stage on which a substrate is placed and connected to the anode; a counter electrode which is arranged so as to face the stage, has a plurality of holes, and is connected to the cathode; and a holding portion , which is arranged so as to face the stage through the counter electrode, and supplies the chemical solution to the counter electrode while holding the counter electrode.

Description

Substrate processing apparatus and substrate processing method

The various embodiments described herein generally relate to a substrate processing apparatus and a substrate processing method.

As one of the substrate processing methods, it is known to perform a process such as etching or oxidizing a metal film formed on a substrate in a state where an electric field is applied.

Embodiments of the present invention provide a substrate processing apparatus and a substrate processing method that are more suitable for metal film processing.

The substrate processing apparatus according to the embodiment includes: a stage on which a substrate is placed and connected to the anode; a counter electrode which is arranged so as to face the stage, has a plurality of holes, and is connected to the cathode; and a holding portion It is arrange|positioned so that it may oppose the stage through the counter electrode, and the chemical|medical solution is supplied to the counter electrode while holding the counter electrode.

According to the above configuration, it is possible to provide a substrate processing apparatus and a substrate processing method that are more suitable for metal film processing.

Hereinafter, a plurality of embodiments will be described with reference to the drawings. In the drawings, the same symbols represent the same or similar parts.

In addition, an embodiment of the present invention will be described below with reference to the drawings. This embodiment does not limit the present invention.

As shown in FIG. 1 , a wafer-like substrate 100 is placed on the turntable 10 . The turntable 10 is rotatable in the rotational direction R about the rotational shaft 10a. On the turntable 10, a plurality of conductive pins 11 electrically connected to the following wires 13 are provided.

As shown in FIG. 2( b ), the plurality of pins 11 are distributed in the rotational direction R, and are in contact with the outer peripheral portion of the substrate 100 . The substrate 100 is fixed to the turntable 10 by a plurality of pins 11 . Each pin 11 is covered by the edge holder 12 to avoid contact with the liquid medicine 200 . The material of the edge holder 12 is preferably a material having corrosion resistance and insulating properties to the chemical liquid 200 , such as Teflon. Furthermore, the fixing method of the substrate 100 is not limited to the method of fixing the outer peripheral portion of the substrate 100 with a plurality of pins 11 as in the present embodiment. The fixing member may also be arranged at a position not in contact with the counter electrode 30 , for example, the back surface of the substrate 100 . The pins 11 are, for example, connected to the substrate 100 at the front end or a film (eg, semiconductor or metal) formed on the surface of the substrate 100 .

The turntable 10 is provided with a lead wire 13 and a lead wire 14 . The wires 13 and 14 electrically connect the plurality of pins 11 to the anodes 51 of the DC power source 50 . Therefore, the potential of the substrate 100 is the same as the potential of the anode 51 . As shown in FIG. 1 and FIG. 2( b ), in this embodiment, one end of the plurality of wires 13 is connected to each pin 11 . The other end of each lead wire 13 is bundled into a lead wire 14 on the rotating shaft 10a. The wire 14 is connected to the anode 51 of the DC power source 50 via the wire 15 . In this way, the substrate 100 is connected to the DC power supply 50 via the pins 11 and the wires 13 to 15 . In addition, between the lead wire 14 and the lead wire 15, a connection portion (not shown) is provided. The lead wire 14 can be rotatably connected to the lead wire 15 in a stationary state by the connecting portion. The connecting portion can also be disposed between the wire 13 and the wire 14 .

The head 20 has a plurality of liquid passage holes, and functions as a liquid supply part in the shape of a spray head. The head 20 rotates synchronously with the turntable 10 at a position opposite to the turntable 10 . An opening 21 is provided on the upper portion of the head 20 . Inside the head 20 , a lead 22 electrically connected to the opposite electrode 30 is disposed. In the present embodiment, the center of the opening portion 21 coincides with the rotation axis 10 a of the turntable 10 . The chemical solution 200 for processing the substrate 100 flows into the opening 21 . Moreover, the lead wire 22 is connected to the cathode 52 of the DC power supply 50 via the lead wire 16 . In this way, the counter electrode 30 is connected to the DC power source 50 via the lead wire 22 and the lead wire 16 . Furthermore, between the lead wire 22 and the lead wire 16, a connection portion (not shown) is provided. The lead wire 22 can be rotatably connected to the lead wire 16 in the stationary state by the connecting portion. The connecting portion may also be disposed between the lead 22 and the opposite electrode 30 .

As the chemical solution 200, an acid, an alkali, an oxidizing agent, a salt, an organic solvent, or the like can be used. Specifically, this chemical solution 200 series sulfuric acid, nitric acid, phosphoric acid, hydrochloric acid, hydrofluoric acid, acetic acid, formic acid, hydrogen peroxide water, ozone water, ammonium persulfate, ammonia water, sodium chloride, sodium hydroxide aqueous solution, hydrogen peroxide Potassium aqueous solution, tetrahydroxyammonium halide, choline, etc.

Since the above-mentioned chemical liquid has strong erosive property, the material of the head 20 is preferably an insulating resin such as polytetrafluoroethylene (PTFE, polytetrafluorethylene) or polychlorotrifluoroethylene (PCTFE, polychlorotrifluoroethylene). In addition, it is preferable that the lead wire 22 is also covered with such an insulating resin.

On the lower part of the head 20 , an annular guide member 23 is arranged along the outer periphery of the head 20 . When the head 20 is rotated, the liquid medicine 200 can be prevented from scattering by the guide 23 . Moreover, since the guide 23 is mounted on the edge holder 12 as shown in FIG. 1, the head part 20 can be positioned. Since the counter electrode 30 is held by the head 20 , the distance between the substrate 100 and the counter electrode 30 is stabilized by fixing the position of the head 20 . The distance between the substrate 100 and the counter electrode 30 is, for example, 1 mm or more, and the substrate 100 and the counter electrode 30 are disposed at positions that are not in contact with each other at all.

The counter electrode 30 is located under the head 20 and is held by the head 20 . That is, the head portion 20 also functions as a holding portion for the counter electrode 30 . The periphery of the counter electrode 30 is surrounded by the conductor 23 . The counter electrode 30 includes, for example, at least one of conductive carbon, platinum (Pt), gold (Au), silver (Ag), and palladium (Pd), and is formed in a circular plate shape. Alternatively, the counter electrode 30 may also include a carbon material covered by a noble metal film or a graphene nanosheet with defects. As shown in FIG. 2 , the counter electrode 30 has a plurality of liquid passage ports 31 in the shape of holes through which the chemical liquid 200 passes.

In addition, the counter electrode 30 is electrically connected to the lead wire 22 . The lead 22 is connected to the cathode 52 of the DC power supply 50 . Therefore, the potential of the counter electrode 30 is the same as that of the cathode 52 . That is, the potential of the counter electrode 30 is lower than that of the substrate 100 .

The fixing jig 40 fixes the head 20 on the rotary table 10 . In the present embodiment, the fixing jig 40 fixes the head 20 and the rotary table 10 at the contact portion of the guide piece 23 and the edge holder 12 . Furthermore, the fixing method of the fixing jig 40 is not particularly limited. For example, the fixing jig 40 can also be fitted with the guide piece 23 and the edge holder 12 respectively.

The DC power source 50 has an anode 51 electrically connected to the substrate 100 and a cathode 52 electrically connected to the counter electrode 30 . When the DC power supply 50 is energized by applying a voltage, an electric field is generated between the substrate 100 and the counter electrode 30 , and the corrosion current flows to the substrate 100 through the chemical solution 200 .

The control unit 60 controls the rotation operation of the turntable 10 , the energization operation of the DC power supply 50 , the supply operation of the chemical solution 200 , and the like. In addition, the control part 60 can also be comprised as the exterior of the substrate processing apparatus 1. As shown in FIG.

Next, an example of the structure of the substrate 100 to be processed will be described with reference to FIGS. 3( a ) and 3 ( b ). FIG. 3( a ) shows a state before the substrate 100 is processed, and FIG. 3( b ) shows a state after the substrate 100 is processed.

As shown in FIG. 3( a ), a metal film 101 is provided on the substrate 100 before processing. The metal film 101 is provided on the laminate 102 . The laminated body 102 is provided on, for example, a semiconductor substrate 110 containing silicon or the like. The metal film 101 is a mask formed on the laminate 102 in order to form a pattern (in this embodiment, a slit penetrating the laminate 102 ) on the laminate 102 , and includes, for example, tungsten.

In this embodiment, the pattern of the laminated body 102 is formed by etching the pattern formed in the metal film 101 as a mask, for example. The metal film 101 is removed by the etching process of the substrate processing apparatus 1 as shown in FIG. 3( b ).

In the laminated body 102, insulating films 102a and conductive films 102b are alternately provided. The insulating film 102a contains, for example, silicon oxide (SiO ₂ ). The conductive film 102b contains tungsten similarly to the metal film 101 . The conductive film 102b can be used, for example, for word lines of a 3D memory. Furthermore, the structure of the substrate 100 is not limited to the above-mentioned structure.

In addition, the application of the substrate processing apparatus 1 is not limited to the etching of the metal film 101 described above. The substrate processing apparatus 1 can also be used for the step of peeling off the conductive film (not shown) formed on the substrate, the step of forming holes on the substrate, or the step of oxidizing the aluminum thin film formed on the substrate to form aluminum oxide holes. These multiple uses can be controlled by the conditions of the film formed on the substrate 100 , or/and the conditions of the chemical solution 200 , or/and the application conditions of voltage.

FIG. 4 is a perspective view showing an example in which holes are formed in the substrate. In FIG. 4, with respect to the substrate 120, the substrate processing apparatus 1 of this embodiment is used, and corrosion current is locally generated. Thereby, the hole 121 is formed. The holes 121 are opened on the surface of the substrate 120 and extend toward the interior of the substrate 120 .

Fig. 5(a) is a perspective view showing a state before alumina pores are formed. Fig. 5(b) is a perspective view showing a state after alumina pores are formed. In FIG. 5( a ), an aluminum thin film 131 is formed on a substrate 130 serving as a silicon substrate. For the aluminum thin film 131, the substrate processing apparatus 1 of the present embodiment is used to locally generate a corrosion current. Thereby, the aluminum thin film 131 is oxidized and grows to the aluminum oxide film 132 . At the same time, a local electric field can be generated in the surface of the aluminum film 131 , and the oxidized aluminum film 131 can be dissolved by the chemical solution 200 supplied to the aluminum film 131 . By repeating this step, a plurality of holes 133 are formed in the aluminum oxide film 132 . In this method, the chemical solution 200 may be used under the conditions containing an acid capable of dissolving alumina, or may be appropriately set under the conditions of voltage application such that the holes 133 are formed at a desired distance.

The above-mentioned holes 133, in other words anodized holes, can be applied to, for example, memory elements. After forming a magnetic thin film in the anodic oxidation hole by CVD (Chemical Vapor Deposition, chemical vapor deposition) method, a cylindrical magnet is obtained. When the current flows from the magnet up and down, the magnetization information in the tube can be displaced up and down, while writing, memorizing, and reading can be performed as a memory element.

Hereinafter, a substrate processing method using the substrate processing apparatus 1 of the present embodiment will be described. Here, the etching step of the metal film 101 shown in FIG. 3( a ) is taken as an example for description.

First, the substrate 100 is fixed to the turntable 10 by a plurality of pins 11 . Thereby, the substrate 100 is electrically connected to the anode 51 of the DC power source 50 through the wires 13 .

Then, the head 20 is lowered to the position where the guide piece 23 contacts the edge holder 12 . Next, the head 20 is fixed to the rotary table 10 by the fixing jig 40 . Thereby, the distance between the counter electrode 30 and the substrate 100 can be stably maintained.

Next, the medicinal solution 200 is introduced into the head portion 20 from the opening portion 21 . The introduced chemical solution 200 is supplied to the substrate 100 from the liquid passage port 31 of the counter electrode 30 via the head 20 . Simultaneously with the supply of the chemical solution 200, the turntable 10 is rotated. Furthermore, energization is started from the DC power supply 50 . By this energization, an electric field is generated in the chemical solution 200 located between the substrate 100 and the counter electrode 30 . As a result, corrosion current flows in the substrate 100 , thereby promoting the etching of the metal film 101 .

According to the present embodiment described above, an electric field is generated between the substrate 100 functioning as an anode and the counter electrode 30 functioning as a cathode by energization from the DC power supply 50 . Thereby, a voltage is applied to the chemical solution 200 supplied from the counter electrode 30, so that the reaction speed of etching or oxidation can be improved.

The chemical solution 200 is supplied from the head-shaped head 20 to the counter electrode 30, so that a desired amount of the chemical solution can be supplied within a desired range. In addition, since the liquid port 31 is provided in the counter electrode 30 , the chemical liquid 200 introduced from the opening 21 can be directly supplied from the counter electrode 30 to the substrate 100 . Therefore, the counter electrode 30 can be arranged on the lower part of the head 20 , whereby the counter electrode 30 can be infinitely approached to the substrate 100 . As the distance between the counter electrode 30 and the substrate 100 approaches, a voltage can be effectively applied to the chemical solution 200 . As a result, the output voltage of the DC power supply 50 can be reduced, and the reaction efficiency can be improved.

Furthermore, when the chemical solution 200 is supplied from the counter electrode 30 to the substrate 100 , the head 20 rotates in synchronization with the turntable 10 . Therefore, the flow rate of the chemical solution 200 is increased, so that the reaction speed of etching or oxidation can be further improved.

(Second Embodiment) FIG. 6 is a schematic view showing a schematic configuration of a substrate processing apparatus according to a second embodiment. The same reference numerals are assigned to the same constituent elements as those of the above-described first embodiment, and detailed descriptions are omitted.

The substrate processing apparatus 2 of this embodiment is the substrate processing apparatus 1 of the first embodiment. The counter electrode 30 includes a plurality of trichomes 32 . That is, instead of the flat-shaped counter-electrode 30, a hair-shaped counter-electrode is included. Hereinafter, the counter electrode will be described as the trichome 32 . As shown in FIG. 6 , the lead wires 22 are individually connected to the plurality of trichomes 32 . The wire 22 is electrically connected to any cathode 52 of the plurality of DC power sources 50 through the wire 16 . On the other hand, the substrate 100 is commonly connected to the anodes 51 of the DC power sources 50 via the lead wires 13 to 15 .

FIG. 7 is an enlarged cross-sectional view of the trichome 32 . The hair-like body 32 is an aggregate of a plurality of hair-like members 33 extending from the head 20 toward the substrate 100 side and gathered together. In each hair-like member 33, the insulator 33a constitutes a core portion. The insulator 33a is covered with a noble metal film 33b. The insulator 33a contains, for example, polypropylene, and the noble metal film 33b contains, for example, a noble metal such as platinum. The trichomes 32 may also include conductive carbon materials.

Furthermore, the hair-like member 33 is not limited to the above-mentioned configuration. For example, the noble metal film 33b may partially cover the insulator 33a, or may cover the entire insulator 33a. In addition, the insulator 33a may be covered with nanoparticles of noble metal.

According to the present embodiment, as in the first embodiment, when the chemical solution 200 is supplied from the liquid passage port 31 of the counter electrode 30 while the turntable 10 is rotated, each DC power supply 50 is energized. At this time, in the present embodiment, not only the counter electrode 30 but also each trichome 32 also functions as a cathode. As a result, the surface area of the portion in contact with the chemical solution 200 is increased, so that the reaction between the chemical solution 200 and the substrate 100 is activated.

Moreover, according to this embodiment, the cathode potential can be controlled by individually adjusting the output voltage of each DC power supply 50 . Therefore, for example, when etching unevenness occurs in the substrate 100 , uniform processing can be performed in the substrate 100 by individually adjusting the output voltage of each DC power supply 50 .

Furthermore, in this embodiment, the number of the wires 13 on the anode side is not limited. Like the lead wire 22 on the cathode side, a plurality of lead wires 13 may be provided on the turntable 10 separately from each other. In this case, since the cathode potential can be controlled, the reaction can be locally activated with respect to the substrate 100 .

(3rd Embodiment) Hereinafter, 3rd Embodiment is demonstrated. The same reference numerals are given to the same components as those of the second embodiment described above, and detailed descriptions are omitted.

In the substrate processing apparatus of the present embodiment, as shown in FIG. 8 , a plurality of mesh bodies 34 are provided as counter electrodes. The upper ends of the plurality of mesh bodies 34 are connected to the lead wires 22 at the lower part of the head 20 similarly to the trichomes 32 . In the mesh body 34, for example, the conductive carbon 35 in the shape of a rope is processed into a mesh (mesh).

According to the present embodiment, as in the second embodiment, when the chemical solution 200 is supplied from the liquid port 31 of the counter electrode 30 through the head 20 while the turntable 10 is rotated, each DC power supply 50 is energized. At this time, in the present embodiment, the mesh body 34 functions as a cathode. Thereby, since the surface area of the contact portion with the chemical solution 200 is increased, the reaction between the chemical solution 200 and the substrate 100 is activated.

Also, in the present embodiment, similarly to the second embodiment, the cathode potential can be controlled by individually adjusting the output voltage of each DC power supply 50 . Therefore, when uneven etching occurs in the substrate 100, for example, by individually adjusting the output voltage of each DC power source 50, uniform processing can be performed in the substrate 100.

(Fourth Embodiment) FIG. 9 is a schematic plan view of the upper part of a substrate processing apparatus according to a fourth embodiment. The same reference numerals are given to the same constituent elements as those of the substrate processing apparatuses according to the first to third embodiments described above, and detailed descriptions thereof are omitted.

In the substrate processing apparatus of the present embodiment, as shown in FIG. 9 , a plurality of flat plate-shaped counter electrodes 30 are arranged radially from the lead wire 22 arranged at the center of rotation. Moreover, the liquid passage 31 is formed between the counter electrodes 30 . In addition, the shape of each opposing electrode 30 may be the hair-like body 32 (see FIG. 7 ) described in the second embodiment or the mesh body 34 (see FIG. 8 ) described in the third embodiment.

FIG. 10 is a diagram showing an example of an etching circuit of the substrate processing apparatus 4 according to the fourth embodiment. In the circuit diagram shown in FIG. 10, the variable resistor Rv is connected to the wire 22 and the wire 13, respectively. The resistance value of the variable resistor Rv is controlled by the control unit 60 .

In the present embodiment, in addition to the variable resistance Rv, the resistance R100, the anode resistance Ra, the chemical resistance R200, and the cathode resistance Rc exist in the current path from the anode 51 to the cathode 52. The resistance R100 is the resistance of the substrate 100 , which is the object to be processed. The resistance of the liquid medicine R200 is the resistance of the liquid medicine 200.

The anode resistance Ra is the resistance of the interface between the substrate 100 and the chemical solution 200 . In this interface, there is also an anode capacitance Ca connected in parallel with the anode resistance Ra. The cathode resistance Rc is the resistance of the interface between the counter electrode 30 and the chemical solution 200 . In this interface, there is also a cathode capacitance Cc connected in parallel with the cathode resistance Rc.

In the corrosion circuit constructed as described above, if the corrosion current is not uniform, the oxidation or dissolution rate of the object to be processed is not uniform. Therefore, in this embodiment, the current/voltage of the corrosion circuit can be locally adjusted by controlling the resistance value of the variable resistor Rv by the control unit 60 . Thereby, the corrosion current in the substrate 100 can be made uniform.

According to the present embodiment, as in the other embodiments described above, when the chemical solution 200 is supplied from the liquid passage port 31 while the turntable 10 is being rotated, each DC power source 50 is energized. Since the liquid passage 31 is formed in the gap between the opposing electrodes 30 , the opposing electrode 30 can be arranged at the lower part of the head 20 . In this way, the counter electrode 30 can be arranged near the substrate 100 . As a result, even if the output voltage of the DC power supply 50 is low, the reaction efficiency can be improved.

Furthermore, in this embodiment, the cathode potential can be controlled by individually adjusting the resistance value of the variable resistor Rv. Therefore, for example, when processing unevenness occurs between the central portion of the substrate 100 and its peripheral portion, the substrate 100 can also be energized by adjusting the energization of the counter electrode 30 facing each portion of the substrate 100 . Uniform processing is carried out inside.

Several embodiments of the present invention have been described, but these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in other various forms, and various omissions, substitutions, and changes can be made without departing from the gist of the invention. These embodiments or changes thereof are also included in the invention described in the scope of the patent application and the scope of its equivalents, as in the scope or gist of the invention.

[Related applications] The present application is based on the benefit of the priority of the prior Japanese Patent Application No. 2018-245620 filed on December 27, 2018, and claims the benefit, which is incorporated herein by reference in its entirety.

1: Substrate processing device 10: Rotary table 10a: Rotating shaft 11: Pin 12: Edge gripper 13, 14, 15, 16, 22 Lead wire 20: Head 21: Opening 23: Guide 30: Counter electrode 31: liquid port 32: hair-like body 33: hair-like member 33a: insulator 33b: precious metal film 34: mesh body 40: jig 50: DC power supply 51: anode 52: cathode 60: control unit 100: substrate 101: Metal film 102: Laminate 102a: Insulating film 102b: Conductive film 110: Semiconductor substrate 120, 130: Substrates 121, 133: Hole 131: Aluminum thin film 132: Alumina film 200: Chemical solution Ca: Anode capacitance Cc: Cathode capacitance R : Rotation direction R100: Resistance R200: Chemical resistance Ra: Anode resistance Rc: Cathode resistance Rv: Variable resistance

FIG. 1 is a schematic view showing a schematic configuration of a substrate processing apparatus according to a first embodiment. Fig. 2(a) is a schematic plan view of the upper part of the substrate processing apparatus shown in Fig. 1, and (b) is a schematic plan view of the lower part of the substrate processing apparatus. Figure 3(a) shows the state before the substrate is processed, and (b) shows the state after the substrate is processed. Fig. 4 is a perspective view showing an example in which holes are formed in the substrate. Fig. 5(a) is a perspective view showing the state before the alumina hole is formed, and (b) is a perspective view showing the state after the alumina hole is formed. Fig. 6 is a schematic view showing the schematic configuration of the substrate processing apparatus according to the second embodiment. Figure 7 is an enlarged cross-sectional view of the trichome. Fig. 8 is a schematic cross-sectional view of the main part of the substrate processing apparatus according to the third embodiment. Fig. 9 is a schematic plan view of the substrate processing apparatus according to the fourth embodiment. FIG. 10 is a diagram showing an example of an etching circuit of the substrate processing apparatus 4 according to the fourth embodiment.

1: Substrate processing device

10: Rotary table

10a: Rotation axis

11: Pin

12: Edge gripper

13, 14, 15, 16, 22: wires

20: Head

21: Opening

23: Guide

30: Counter electrode

40: Jig

50: DC power supply

51: Anode

52: Cathode

60: Control Department

100: Substrate

200: liquid medicine

R: direction of rotation

Claims (7)

A substrate processing apparatus, comprising: a stage on which a substrate is placed and connected to an anode; an edge holder having insulating properties and disposed on the outer periphery of the stage so as to cover a fixing member for fixing the substrate The structure is as follows: a counter electrode, which is arranged in a manner opposite to the above-mentioned table, exposes the surface opposite to the above-mentioned table, has a plurality of holes, and is connected with the cathode; a guide member is placed on the above-mentioned edge holder, and provided along the outer periphery of the counter electrode; and a holding part which is arranged so as to face the table with the counter electrode interposed therebetween, and supplies a chemical solution to the counter electrode while holding the counter electrode. The substrate processing apparatus of claim 1, wherein the stage and the holding portion rotate in synchronization. The substrate processing apparatus according to claim 1 or 2, wherein the counter electrode is plate-shaped. The substrate processing apparatus according to claim 1 or 2, wherein the counter electrode is a trichome or a mesh body. The substrate processing apparatus according to claim 1, wherein the substrate and the counter electrode are in non-contact. The substrate processing apparatus according to claim 4, wherein a plurality of the counter electrodes as the trichomes or the mesh body are arranged to be separated from each other, and the plurality of counter electrodes are arranged radially from the center of rotation. A substrate processing method comprising placing a substrate on a stage, connecting the substrate to an anode, and arranging an edge holder having insulating properties so as to cover a fixing member for fixing the substrate on the outer periphery of the stage , the counter electrode having a plurality of holes and connected to the cathode is arranged so as to face the table, the surface of the counter electrode facing the table is exposed, and the guide is placed on the edge holder on top of the counter electrode and along the outer periphery of the counter electrode, and while holding the counter electrode by a holding portion arranged so as to face the stage through the counter electrode, the counter electrode is held from the holding portion while the counter electrode is held. Electrodes are supplied with chemical solution.

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